JPS596693A - Control signal transmission system in key telephone exchange - Google Patents

Abstract

PURPOSE:To enable main wire call and extension call simultaneously using small number of cables by constituting control signal sent and received between main equipment and telephone set and between telephone sets of a row of signal of frequency out of audio frequency band. CONSTITUTION:Control signal sent from a main equipment ME to a telephone set TEL is made by a microcomputer COMM and converted to a row of AC signals of frequency outside audio frequency band by a data sending and receiving circuit DEMM. Converted row of signals are inputted to DEMT of TEL through extension circuits P1, P2 and converted again to pulse code, and inputted to COMT. The control signal sent from TEL to ME is transmitted through a path reverse in direction to above-mentioned path. Control signal sent and received between TEL is transmitted from COMT of sender's TEL to COMT of receiver's TEL through P1, P2. Extension call is transmitted from extension C/O to call circuit net NET through extension circuits L1, L2 and voice of extension call and control signal do not give influences to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control signal transmission method for controlling connection of a simple telephone exchange device, for example, a button composing device.
In particular, the present invention relates to a control signal transmission system that can reduce the number of connection cables without restricting communication between a main device and key telephones or between key telephones.

Conventionally, a pushbutton telephone device in which one central office line C10 is accommodated and the main device ME and the telephone installation are connected by four cables has been configured in a manner as shown in FIG. 1 or 2, for example. Of the four cables L1, L2, C1, and C2, two cables Ll and L2 are used for telephone calls, and the other two cables C1 and C2 supply power to the control unit when the telephone is installed. There have been proposals for use as a power supply line for controlling connections and as a control signal line for transmitting control signals for connection control.

The conventional example shown in FIG. 1 is a system in which each button telephone (hereinafter referred to as a telephone) is connected to the main device ME in multiple ways.
There is one telephone line between E and the telephone installation and between each telephone installation.
Since there is only a line, if one of the composing devices is talking to the central office line C/Q, it is impossible to make an extension call between other telephone installations at the same time, and vice versa. When an extension call is being made, you cannot make a call to the central office line from another telephone at the same time.

Furthermore, in the conventional example shown in FIG. 2, each telephone TgL is connected to the main device ME separately. According to this method, telephone calls to the central office and extension calls are made using separate telephones +S, 'l.
``Although it can be done at the same time with EL, when making an extension call to a telephone installed that is making a call to a local office line, it is not possible to make an extension call using a voice call because the voice route is not already used for a call to the local office line.

The present invention has been made to solve the above-mentioned conventional drawbacks, and the structure of the cable connecting the main device ME and the telephone installations and between the telephone installations is different from the conventional one shown in FIG. It is an object of the present invention to provide a button telephone device having a structure similar to that of the above example, in which the number of cables is reduced, but central telephone calls and extension calls can be made simultaneously within the same telephone or between other telephones.

For this purpose, in the present invention, one set of two cables is used as a central office line, and the other set of two cables are used as an extension line and an ia1 control line.
The control signal is transmitted by intermittent alternating current signals having frequencies outside the audible frequency band, so that the voice signal and control signal for internal calls can be distinguished and transmitted simultaneously. I decided to do so.

Hereinafter, the present invention will be explained in detail with reference to FIGS. 3 and 4.

FIG. 3 shows a basic block diagram of an embodiment of the invention, and FIG. 4 is a block diagram showing details of an embodiment of the invention.

In Figures 3 and 4, C10 is the central office line, ME is the main equipment,
is the telephone, Ll-L2 is the office line communication line (office line line),
PI-P2 is an extension line (extension line), and C is the central office line C10.
The office line control circuit COM, which receives call signals from the station and holds the office line, is a microcomputer, Dh
:M is a data transmitting/receiving circuit that sends and receives control signals, FIL is a filter that removes unnecessary components of signals being sent and received (passes only necessary components), and AVR is a constant voltage of 1! source circuit, NET is a communication circuit network, RY is a switching relay for selecting a communication path, ry is a contact of relay RY, TRP is a trap circuit that passes only signals within the audible frequency band (voice signals), AMP is a call circuit An amplifier that amplifies a signal or a calling voice, and SP is a speaker. In the following explanation, in order to distinguish between circuits with the same function that are present in both the main device M and the telephone installation, circuits of the main device M will be replaced with the circuits in the telephone installation. Items listed below will be explained with a mark (■) attached to them. (If there is no need to distinguish between them, do not mark (goods) or
As shown in the figure, the office line communication lines Ll-L2 are housed directly in the telephone equipment. This is because, as is clear from FIG. 4, switching between the office line Ll-L2 and the extension line PI-P2 is performed within each telephone installation.

That is, in FIG. 4, the telephone installation is provided with a switching relay RY for selecting a communication path, and its contact ry allows the telephone installation to switch between the office line communication path Ll-L2 or the extension communication path PI.
- It is designed to selectively supplement P2. The operating power for the switching relay RY and various control circuits in the telephone installation is supplied from the constant voltage circuit AVR■ of the main device ME to the extension line Pl-P2.
Supplied via.

That is, the power supplied from the constant voltage circuit AVR (Incorporated) of the main device ME to the telephone installation via the extension line Pl-P2 is once input to the constant voltage circuit AVR■ in the telephone T#2L, where the telephone It is stabilized to a voltage suitable for ground control (
Constant voltage circuit AV due to line resistance of extension line p1-P2, etc.
Since the output voltage of R (Incorporated) fluctuates, it is necessary to stabilize the voltage at each telephone installation. ) is supplied to each circuit. In addition, since the output of the constant voltage circuit AVR (M) in the main device ME is directly connected to the extension line Pl-P2, if its output impedance is low, the constant voltage circuit AVR (M
), and the voice signal is attenuated, making it impossible to transmit a sufficient voice signal between telephones through the circuit network NET. Therefore, a constant voltage circuit with high output impedance is used for the constant voltage circuit AVR (Incorporated). be done.

The control signal sent from the main device ME to the telephone installation is generated by the microcomputer 00M of the main device M, and is input to the data transmitting/receiving circuit DEM. The calling signal received by circuit C is input to the microcomputer COM, and each telephone installed has a control signal for displaying an incoming call on the central office line.

The control signal outputted from the microcomputer COM is in the form of a pulse train code, and cannot be transmitted as is. Therefore, the data transmitting/receiving circuit 1) EM1 converts the control signal consisting of the pulse train code into an alternating current signal train having a frequency outside the audible frequency band. The spectrum of the control signal after being converted into an AC signal string has wide frequency components, so if it is sent as is to the extension line P1-P2, it will interfere with the extension phone call using voice within the audible frequency band, so a filter is used. After eliminating the component within the audible mantissa band of the control signal in FILIMl, it is sent to the extension lines 1P1-P2. That is, the filter FILoka has the function of a bypass filter that cuts signals in the audible frequency band.

The control signal sent to the extension communication path P1-P2 is transferred to the communication circuit network NET due to the presence of the trap circuit TRP, which is a circuit that exhibits high interference with the frequency band of the control signal. This prevents the control signal from being attenuated and its reception level from decreasing, and also prevents unnecessary control signals from being input to the communication network NET.

The control signal inputted to the telephone installation as described above is transmitted to the audible frequency band signal blocking filter FI which blocks the passage of the call voice signal flowing to the extension line PI-P2 during an extension call.
The signal passes through L■ and is input to the data transmitting/receiving circuit DJ6M■. That is, the filter F I L
The filter FIL (which has the function of a bypass filter that cuts signals in the audible frequency band like Tl, attenuates the audio signal flowing to the extension line p1-p2, and transmits only the control signal to the data transmission/reception 45 circuit 1) EM■ This prevents input and control signals from being distorted by voice over the phone.

A control signal based on an AC signal train inputted to the data transmitting/receiving circuit DEM2 is reconverted into a pulse train code by the data transmitting/receiving circuit DEM2, and is inputted to the microcomputer COM2. The microcomputer COM (T5) performs signal processing according to a preset program, and performs requested controls, such as displaying an incoming central line call on each telephone, activating the amplifier AIVIP of the audible sound display, and turning on the speaker. Control is performed from the SP to emit a station line ring tone.

The control signal sent from the telephone i to the main device ME includes [
FlJ has a control signal to hold the central office line C10 during a call to the central office line C/Q. Such control signals are transmitted to the telephone T.
The microcomputer COMcD can be
Similarly to the control signal sent from the main device ME to the telephone installation, the signal is converted by the data transmitting/receiving circuit DEM and the unnecessary signal component is removed by the filter FILfT. earthenware [IVIg
The main device ME performs unnecessary signal component removal processing in the filter FtL (foundation) and data transmission/reception circuit ITEM (
The signal is reconverted in the microcomputer COM (c) and then input to the microcomputer COM (c). Microcomputer C
At the OM port, signal processing is performed in accordance with a preset program, and controlled control, for example, station line hold control in the station line control circuit C, is performed.

Control signals exchanged between telephone installations include, for example, a busy display control signal for a central office line or an extension line, a calling control signal for an extension line, and the like. These control signals are transmitted through routes on the transmitting side and on the receiving side, and are processed in the same way as the above two types of control signals in each circuit. If the control signal is, for example, an extension call control signal, the amplifier AMP is activated in the telephone TgL on the receiving side of the control signal, and the internal call ring tone or extension call sound is emitted from the speaker SP.

Extension calling voice (in the case of voice calling method) and extension mutual conversation voice are transmitted to the telephone TgL through the following routes.
It is given and received between each other.

(Extension calling voice) (However, the switching relay of the caller's caller line device) LY is operating. ) (Extension intercom voice) Calling party location Calling party location (however,
The switching relay RY is operating in both telephone installations. ) The trap circuits TRP in each of the above routes exhibit high impedance in the frequency band of the control signal (outside the audible frequency band) as described above.

It has the function of a single-shot low-pass filter that passes only signals in the audible frequency band, that is, voices, among the signals flowing to the extension line PI-P2. Therefore, no signals other than voice flow through the communication network NET or the amplifier AMPK, and the transmission and reception of voice through the above two routes is not disturbed by the control signal.

Also, the office line call is routed to the next route C104-+L via the office line Ll-L2, which is separate and independent from the extension line PI-P2.
1, L2→ry←NET (however, the switching relay RY is inactive), so the central office line conversation voice and the control signal do not affect each other. In other words, it is possible to transmit the voice of the central office line, the voice of the internal telephone call, and the control signal at the same time, and it is not only possible to carry out the central telephone conversation and the internal telephone conversation in parallel, but also to perform various control operations in between. .

By the way, as is clear from FIG. 4, the extension communication path PI-
An amplifier AMP is always connected to P2, and various advantages are produced by providing an audio switch circuit in front of the input circuit of the amplifier AMP to control the operation of the amplifier AMP. In other words, as mentioned above, since it is possible to make an extension call even during a call on the local line, even if a telephone installed during a call on the local line or receiving an incoming call receives an extension call from another telephone installed, A voice call can be received by operating the voice switch circuit. In addition, if a hands-free function (so-called function to make amplified calls using a speaker and microphone without using a handset) is added to the telephone installation (switching relay contact RY and trap circuit TRP, similar to the amplifier AMP in the IIT telephone device) ) Even if there is an extension voice call during a call on the local line or during an incoming call on the local line, it is possible to respond to the voice call.

As is clear from the above explanation, according to the present invention, the control signal is converted into voice or a signal in a frequency band different from the voice signal and transmitted via the extension line. Mutual communication and control signal transmission can be performed simultaneously without affecting each other.In addition, by adding a voice switch function, a noise-free function, etc. to the incoming audible display circuit, central office lines can be transmitted even within the same telephone. The present invention has advantages in terms of the structure and operation of the device, such as being able to make a call and display an extension call, or make a call to a central office line and a noise-free call to an extension, etc., without increasing the number of connection cables. In the example, the number of accommodated office lines and extension lines is one line each, and the number of cables is four, but the number of accommodated office lines and extension lines and the number of cables This does not change the purpose of the invention.

[Brief explanation of drawings]

1 and 2 are block diagrams showing a conventional example, FIG. 3 is a block diagram showing an embodiment of the present invention, and FIG. 4 is a block diagram of a specific circuit configuration of the embodiment of the present invention. (Main symbols) Ll, L2... Office line communication path (office line line) Pl, p2.
...Extension communication line (extension line) that also serves as a control line ME...Main equipment Placement...Telephone CO ■[...
- Microcomputer DEM...Data transmission/reception circuit T RP...Trap circuit AMP...Amplifier for calling extension 1 RY...Call path switching relay NET...Telephone circuit network. Figure 1 Figure 2 Figure 3 573- Procedural Amendment Document Showa 5g Year Month 2? [J Patent Office Commissioner Aimoto Shi D Shakudo 1, Indication of the case Showa 7 Handheld 5'1 Relationship to Case No. 11520ρ Applicant 4, Zangetsu I Address 2-chome, Marunouchi, Chiyo I'11-ku, Tokyo 6 No. 2 Marunouchi to Shigesu Building 330 The following matters in the specification of the present application will be amended as shown in column 8 of the explanation of the invention =YIm' in the attached document. Note 1, page 4, line 13, the phrase ``station line control circuit'' has been revised to ``station line control circuit.'' 2. In the 4th and 6th lines of page 5, "Main device M" is corrected to "Main device MEJ." 3. On the 2nd line of page 11, it says ``Internal delivery''. Correct it to ``Internal delivery.''

Claims (1)

[Claims] In a simple telephone switching device that has a central office line that connects to any of multiple telephones and an extension line that connects each telephone, the control signals sent and received between the main device and the telephone and between the telephones are transmitted at an audible frequency. A control signal transmission system for a simple telephone exchange device, comprising an alternating current signal train of a frequency outside the band, and transmitting the control signal through the above-mentioned extension line.